Description

The stobsl() and stobclear() functions translate character-coded labels into binary labels. They
also modify an existing binary label by incrementing or decrementing it to
produce a new binary label relative to its existing value.

The calling process must have PRIV_SYS_TRANS_LABEL in its set of effective privileges
to perform label translation on character-coded labels that dominate the process's sensitivity
label.

The generic form of an input character-coded label string is:

[ + ] classification name ] [ [ + | - ] word ...

Leading and trailing white space is ignored. Fields are separated by white
space, a `/' (slash), or a `,' (comma). Case is irrelevant. If
string starts with + or -, string is interpreted a modification to an
existing label. If string starts with a classification name followed by a
+ or -, the new classification is used and the rest of
the old label is retained and modified as specified by string. +
modifies an existing label by adding words. - modifies an existing label
by removing words. To the maximum extent possible, errors in string are
corrected in the resulting binary label label.

The stobsl() and stobclear() functions also translate hexadecimal label representations into binary
labels (see hextob(3TSOL)) when the string starts with 0x and either NEW_LABEL or
NO_CORRECTION is specified in flags.

The flags argument can take the following values:

NEW_LABEL

label contents is not used, is formatted as a label of the relevant type, and is assumed to be ADMIN_LOW for modification changes. If NEW_LABEL is not present, label is validated as a defined label of the correct type dominated by the process's sensitivity label.

NO_CORRECTION

No corrections are made if there are errors in the character-coded label string. string must be complete and contain all the label components that are required by the label_encodings file. The NO_CORRECTION flag implies the NEW_LABEL flag.

0 (zero)

The default action is taken.

The error argument is a return parameter that is set only if
the function is unsuccessful.

The stobsl() function translates the character-coded sensitivity label string into a binary
sensitivity label and places the result in the return parameter label.

The flags argument can be either NEW_LABEL, NO_CORRECTION, or 0 (zero). Unless
NO_CORRECTION is specified, this translation forces the label to dominate the minimum
classification, and initial compartments set that is specified in the label_encodings file and
corrects the label to include other label components required by the label_encodings
file, but not present in string.

The stobclear() function translates the character-coded clearance string into a binary clearance
and places the result in the return parameter clearance.

The flags argument can be either NEW_LABEL, NO_CORRECTION, or 0 (zero). Unless
NO_CORRECTION is specified, this translation forces the label to dominate the minimum
classification, and initial compartments set that is specified in the label_encodings file and
corrects the label to include other label components that are required by
the label_encodings file, but not present in string. The translation of a
clearance might not be the same as the translation of a sensitivity label.
These functions use different tables of the label_encodings file that might contain
different words and constraints.

Return Values

These functions return 1 if the translation was successful and a valid
binary label was returned. Otherwise they return 0 and the value of
the error argument indicates the error.

Errors

When these functions return zero, error contains one of the following values:

-1

Unable to access the label_encodings file.

0

The label label is not valid for this translation and the NEW_LABEL or NO_CORRECTION flag was not specified, or the label label is not dominated by the process's sensitivity label and the process does not have PRIV_SYS_TRANS_LABEL in its set of effective privileges.

>0

The character-coded label string is in error. error is a one-based index into string indicating where the translation error occurred.

Files

/etc/security/tsol/label_encodings

The label encodings file contains the classification names, words, constraints, and values for the defined labels of this system.

See Also

Notes

The functionality described on this manual page is available only if the
system is configured with Trusted Extensions.

In addition to the ADMIN_LOW name and ADMIN_HIGH name strings defined in
the label_encodings file, the strings “ADMIN_LOW” and “ADMIN_HIGH” are always accepted as character-coded
labels to be translated to the appropriate ADMIN_LOW and ADMIN_HIGH label, respectively.

Modifying an existing ADMIN_LOW label acts as the specification of a NEW_LABEL
and forces the label to start at the minimum label that is
specified in the label_encodings file.

Modifying an existing ADMIN_HIGH label is treated as an attempt to change
a label that represents the highest defined classification and all the defined
compartments that are specified in the label_encodings file.

The NO_CORRECTION flag is used when the character-coded label must be complete
and accurate so that translation to and from the binary form results
in an equivalent character-coded label.